Adding OpenFile/CloseFile to SmbProvider and the corresponding fake.

Bug: 757625
Change-Id: I7379b2a5358f05d9b790f3f3b7e5ade7c9246f78
Reviewed-on: https://chromium-review.googlesource.com/840825
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#525859}
4 files changed